The present invention is directed to a method for extracting metals from metal sulfides. More specifically, the invention is directed to a hydrometallurgical process of a type generally known as chloride leaching, wherein a metal sulfide mineral feed material, in particular a copper sulfide, is treated to produce a commercially saleable grade of metal, in particular copper. According to a particular embodiment of the invention, a copper sulfide mineral is introduced into an aqueous solution having dissolved therein cupric and chloride ions, in which the copper sulfides are converted into acid-soluble copper compounds. This is followed by acid leaching, solvent extraction, and electrowinning to produce cathode copper.
Many methods for treatment of sulfide minerals to recover metals therefrom are already known in the art. Two of the principal types are (1) roast/leach/solvent extraction/electrowinning processes and (2) chloride hydrometallurgical processes. None of the known methods, however, is entirely satisfactory with respect to the efficiency of operations on a commercial scale.
Accordingly, it is an object of the present invention to provide a technologically simple hydrometallurgical process for treating copper sulfide minerals to produce a commercially saleable product, which process achieves a high degree of processing per unit volume, leaves pyrite unreacted, and operates at a low temperature and pressure.